• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2003년도 춘계 학술발표회논문집
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• pp.385-392
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• 2003

Experimental investigation was conducted into the flexure/shear-critical behavior of earthquake-damaged reinforced concrete columns with lap splicing of longitudinal reinforcement in the plastic hinge region. Six test specimens in the aspect ratio of 2.5 were made with test parameters: confinement ratios, lap splices, and retrofitting FRP materials. They were damaged under series of artificial earthquakes that could be compatible in Korean peninsula. Directly after the pseudo-dynamic test, damaged columns were retested under inelastic reversal cyclic loading simultaneously under a constant axial load, P = 0.1 $f_{ck}$ $A_{g}$. Residual seismic performance of damaged columns was evaluated and compared to that of the corresponding original columns. Test results show that RC bridge piers with lap-spliced longitudinal steels in the plastic hinge region appeared to fail at low ductility. This was due to the debonding of the lap splice, which resulted from insufficient development of the longitudinal steels. The specimens externally wrapped with composite FRP straps in the potential plastic hinge region indicated significant improvement both in flexural strength and displacement ductility.y.

• Computers and Concrete
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• 제2권5호
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• pp.367-380
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• 2005

Recent earthquakes have shown that many of existing buildings in Iran sustain heavy damage due to defective seismic details. To assess vulnerability of one common type of buildings, which consists of low rise framed concrete structures, three defective and three standard columns have been tested under reversed cyclic load. The substandard specimens suffered in average 37% loss of strength and 45% loss of energy dissipation capacity relative to standard specimens, and this was mainly due to less lateral and longitudinal reinforcement and insufficient sectional dimensions. A relationship has been developed to introduce variation of plastic length under increasing displacement amplitude. At ultimate state, the length of plastic hinge is almost equal to full depth of section. Using calibrated hysteresis models, the response of different specimens under two earthquakes has been analyzed. The analysis indicated that the ratio between displacement demand and capacity of standard specimens is about unity and that of deficient ones is about 1.7.

• 한국컴퓨터정보학회논문지
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• 제6권4호
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• pp.179-187
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• 2001

본 논문은 대학생들의 정보화에 대한 인식과 정보화의 실태를 조사 분석하여 그 문제점을 지적하고 대책을 제시하여 이를 정보화 교육에 잘 활용하기 위한 목적을 가지고 있다. 연구의 결과로 정보화 통신매체는 소득수준이 높은 수도권이 보급 비율이 높은 것으로 나타났으며, 정보화 매체의 활용이 아직 미흡하고. 학생들의 정보화 매체 이용에 따른 비용부담이 아직 부모에게 의존하는 경향이 많으며, 정보화교육이 사설학원에 많이 의존하고있다는 것이 지적되었다. 이를 위해 정보화를 위한 장비 보급의 균등화, 올바르고 효율적인 정보 활용에 관한 교육 프로그램의 개발, 정보화 비용부담을 줄이기 위해서는 필요하지 않은 매체 이용의 가급적인 자제, 정보화 교육에 있어서 학교의 역할 등이 필요한 것으로 나타났다.

• 산업융합연구
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• 제2권2호
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• pp.31-46
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• 2004

The ratio of industrial injury in Korea is higher 2~4 times than advanced nations like Japan and Singapore, because the industrial injuries in small-medium industry are higher than large size industry. The investment ability is insufficient for working conditions and prevention of the industrial injuries in the small & medium industry. The industrial safety management of machinery manufacturing for transportation, chemical factory, textile product manufacturing, wire & circuit products for computer, plastic goods manufacturing, and metal products manufacturing was investigated. Therefore, the purpose of the paper is to recognize the seriousness of the industrial injuries, understand product, layout, and machinery, and working conditions, etc., and indicate safety engineering techniques for improvement of quality and productivity under this safety working conditions.

• Journal of Information Processing Systems
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• 제17권6호
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• pp.1083-1096
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• 2021

Compressed sensing-based matching pursuit algorithms can estimate the sparse channel of massive multiple input multiple-output systems with short pilot sequences. Although they have the advantages of low computational complexity and low pilot overhead, their accuracy remains insufficient. Simply multiplying the weight value and the estimated channel obtained in different iterations can only improve the accuracy of channel estimation under conditions of low signal-to-noise ratio (SNR), whereas it degrades accuracy under conditions of high SNR. To address this issue, an improved weighted matching pursuit algorithm is proposed, which obtains a suitable weight value u_op by training the channel data. The step of the weight value increasing with successive iterations is calculated according to the sparsity of the channel and u_op. Adjusting the weight value adaptively over the iterations can further improve the accuracy of estimation. The results of simulations conducted to evaluate the proposed algorithm show that it exhibits improved performance in terms of accuracy compared to previous methods under conditions of both high and low SNR.

• 공업화학
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• 제33권6호
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• pp.661-665
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• 2022

In this study, 2,5-dichlorobenzophenone was synthesized as a monomer using 1,4-dichlorbenzene, and subsequently, copolymers of benzoyl-p-phenylene and p-phenylene were prepared. The average molecular weight was improved using the low-molecular-weight polymer cutting method. The average molecular weight and glass transition temperature of the synthesized polymers were estimated. The as-prepared polymer was used as a hard coating material, and the coating was conducted on a poly(methyl methacrylate) plate. Furthermore, physical properties of the coatings, such as pencil hardness, adhesive strength, and abrasion resistance, were estimated. As the amount of p-phenylene in the copolymer increased, pencil hardness and abrasion resistance improved. The amount of p-phenylene in the copolymer can be increased to 30 mol% in order to increase the hardness of the coating, and the adhesive strength was insufficient for the copolymers with p-phenylene ratio greater than 35 mol%.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.170-171
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• 2022

In recent years, due to the occurrence of traffic accidents caused by black ice in winter, the number of personal injuries is increasing rapidly. Black ice is a phenomenon that occurs like a thin layer of ice on the road surface. Accordingly, many developments of heat-generating concrete are being developed to remove ice by increasing the temperature by supplying constant electricity to places where black ice is likely to occur. These heating elements are being developed by mixing a conductive material represented by carbon nanotubes with concrete. However, research up to now has been focused on efficient temperature rise and derivation of the optimum mixing ratio, and the evaluation of maintaining heat generation performance during continuous repetition is insufficient. Therefore, in this study, a heating test specimen was manufactured and 50V power was repeatedly supplied to evaluate the heating characteristics.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권6호
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• pp.590-594
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• 2006

Dental implant has become one of the important option for completely or partially edentulous patients, But it is challenging to reconstruct the severely atrophic ridge. Insufficient bone volume could restrict to place the wide and long implant and because of excessive interocclusal clearance, improper prosthetics could be produced. In this case bone augmentation for implant dentistry is necessary procedure to improve the insufficient bone volume. Therefore, bone augmentation or GBR is the most important procedure for successful implant placement and for ideal crown- root ratio. There are various bone augmentation techniques have been introduced recently; like block bone graft, distraction osteogenesis, inlay graft, onlay graft, etc.... In severe bucco-lingual resorption area, ridge splitting is the first choice of the treatment, because it provides a place for implantation and also has compaction effect. This technique may be indicated for sharp mandible and maxillary ridges in patients whose bone quantity is inadequate for primary stabilization. We report that the clinical experience of bone augmentation using ridge splitting technique in bucco-lingual bone resorption area.

• 한방비만학회지
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• 제9권1호
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• pp.59-69
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• 2009

Objectives This study was designed to evaluate the difference of between Kyungohkgo and Kyungohkgo Ga Nokyong effects of growth Methods We divided male Spraque-Dawley rats into 6 groups. They were Normal group, Growth deficiency rat with insufficient nutrition diet group, Growth deficiency rat with 0.1% Kyungohkgo group, Growth deficiency rat with 0.2% Kyungohkgo group, Growth deficiency rat with 0.1% Kyungohkgo Ga Nokyong group and Growth deficiency rat with 0.2% Kyungohkgo Ga Nokyong group. They were administered for 5 weeks. We measured body weight, serum growth hormone, insulin-like growth factor and thyroid stimulating hormone, RBC, concentration of Hb and PCV ratio, total WBC and its composition, the values of plasma glutamic oxaloacetic transaminase(GOT) and glutamic pyruvic transaminase(GPT) activities. Results 1. In body weight, Kyungohkgo 0.1%, Kyungohkgo Ga Nokyong 0.1%, 0.2% groups were showed sighnificantly different than control group. But That groups were not showed significantly different than each others. 2. In serum growth hormone, insulin-like growth factor and thyroid stimulating hormone, we obtained the results of tendency to increase in Kyungohkgo Ga Nokyong group, however these values showed no significantly different. 3. In the counts of RBC, Kyungohkgo group and Kyungohkgo Ga Nokyong group were showed significantly different than control group. But these values showed no significantly different. In the concentration of Hb, Kyungohkgo Ga Nokyong 0.2%group was showed significantly different than control group. Kyungohkgo Ga Nokyong 0.2% group and Kyungohkgo 0.2% group were showed significantly different than control group. 4. The counts of total WBC and its composition showed no significantly different in all treatment groups. 5. The values of plasma glutamic oxaloacetic transaminase(GOT) and glutamic pyruvic transaminase(GPT) activities showed no significantly different in all treatment groups. Conclusions So Kyungohkgo Ga Nokyong and Kyungohkgo have an effect of promoting growth of rats. And We know that the effect of Kyungohkgo Ga Nokyong is better than Kyungohkgo.

• 컴퓨터교육학회논문지
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• 제20권4호
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• pp.37-46
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• 2017

2018년부터 중학교에서 필수로 실시되는 정보교육의 수준은 정보 컴퓨터 교사의 교과전문성에 의존한다. 본 연구는 중등 교사양성기관이 정보 컴퓨터 교사의 교과전문성을 담보하는 교육과정을 제공하고 있는지 분석하기 위한 목적이 있다. 목적 달성을 위해 첫째, 한국 중등 교사양성기관의 정보 컴퓨터 교사양성을 위한 교육과정 과목을 일본 정보학 분야 고등정보교육과정인 J07-CS의 내용체계를 기반으로 구성된 과목과 비교하였다. 둘째, 교육부에서 제시하는 기본이수과목과 비교하고 셋째, 각 대학의 기본이 수과목 개설 현황도 분석하였다. 연구 결과, 중등 교사양성기관에서 개설되는 정보관련 과목 수는 J07-CS의 과목 수와 비교하여 부족하였다. 비교기준을 기본이수과목으로 한정해도 내용요소가 부족하였고, 교사양성기관별 기본이수과목의 개설 비율도 낮았다. 2018년부터 실시되는 정보교육의 목표를 원활이 달성하기 위해서는 중등 교사양성기관의 교육과정에 대한 개선이 시급하다.